A BHP rail maintenance crew applied brakes to the wrong locomotive when they tried to help the driver of a runaway iron ore train, which ended up being deliberately derailed in Western Australia's Pilbara region.
The fully-laden, 2.86 kilometre-long train hurtled along BHP's Newman to Port Hedland line for about 50 minutes on November 5, leaving behind driver Peter Frick.
The calamity unfolded after a communication fault between the front of the train and a monitor at the end of the locomotive triggered an automatic brake.
According to a preliminary report released by the Australian Transport Safety Bureau on Tuesday, Mr Frick raised the alarm with the control centre and confirmed handbrake requirements before applying an "independent" brake.
He then got out to manually apply handbrakes to the 268 ore cars while awaiting help from a maintenance crew.
They were to work from the back of the train, while he was to continue working his way down from the front.
Instead, the crew mistakenly applied handbrakes to an empty ore train that had been instructed to stop and move to a safe place while the emergency efforts were underway.
Meanwhile, the braking system that initially stopped the fully-laden train automatically released after one hour while Mr Frick was still outside.
"Even if the track support team had have attended the correct train and applied manual brakes, it would not have been enough to stop the roll-away event," a BHP spokeswoman said in an emailed statement.
The train reached a top speed of 162km/h before slowing to 144km/h when it was derailed, destroying two locomotives, 245 ore cars and 2km of track infrastructure at Turner South.
Mr Frick was sacked, with BHP saying an internal investigation showed the accident was the result of his "procedural non-compliance".
WA iron ore asset president Edgar Basto said Mr Frick did not apply the automatic brake handle to the emergency position as required and as he had been trained to do.
"If the automatic brake handle was in the emergency position as per the operating procedure, the train would not have rolled away," Mr Basto said.
BHP also admits "integration issues with the electronically-controlled pneumatic braking system" contributed to the accident.
Mr Frick has since reached a confidential settlement with BHP after taking his case to the Fair Work Commission.
CFMMEU Mick Buchan recently told AAP the blame levelled at Mr Frick was "a disgrace".
